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Sixteen frame-mounted fascia lata valves removed from the mitral, aortic or--in one patient--pulmonary position have been detailed histologically. These valves had remained in 15 patients (11 men and four women) for periods varying between 10 and 44 months. The reason for the original transplantation was either chronic rheumatic endocarditis or calcific aortic disease. In the mitral position, the leaflet in position nearest the site of the original anterior mitral valve cusp showed the least changes. The remaining two leaflets of the fascia lata valve in the mitral position, as well as those removed from the aortic or pulmonary position, showed more severe changes; these consisted of degeneration of collagen tissue and often a severe decrease of nuclei belonging to the fibroblastic series. These changes, as well as superimposition of fibrin or fibrous tissue, tended to become more pronounced the longer the valve had remained in the patient. Viability studies in valves removed from two patients have also been undertaken showing very greatly reduced activity. The possible causes for valve dysfunction have been reviewed, and the findings in this study suggest that contraction of fibrous tissue, which sandwiches the fascia lata valve cusps, may contribute to failure of satisfactory valve function. It is concluded that fascia lata forms a poor substitute for replacement of diseased cardiac valves. [ABSTRACT FROM PUBLISHER]

Accumulated evidence indicates that fresh aortic valve homografts function longer than preserved grafts. Thus it becomes important to assess the viability of fresh homografts on a quantitative basis. Recently, we have used autoradiography in addition to tissue culture to determine the viability of fresh aortic and pulmonary valve homografts. The uptake of thymidine was gradually reduced to 50% after 18 days of preservation in a balanced salt solution with antibiotics and the uptake was reduced to 21% in 63 days. We think that a nutrient medium is necessary if longer viability is to be obtained. [ABSTRACT FROM PUBLISHER]

The present study was undertaken to find an antibiotic mixture which would rapidly and completely sterilize a heavily contaminated allograft heart valve without reducing its viability. Two different antibiotic combinations were used; formula A was used for 66 valves and formula B for 60 valves. Viability of the valves was assessed by autoradiography and tissue culture, and was found to be similar in both formulae. Formula B proved more effective; all valves were sterile after 24 hours' exposure to the antibiotics and remained so thereafter. The period of viability was greatly extended when a nutrient medium was used to store the valves. [ABSTRACT FROM PUBLISHER]